The present invention relates to a system for controlling model trains.
A primary goal of model train system designers and builders is to make the model train experience as realistic and as satisfying as possible for the user. To enhance the user's experience, model train layouts commonly include elaborate scale scenery, several tracks, and multiple trains. The features and functions of a model train layout, such as track switches or turnouts, signals, and locomotives, are commonly remotely actuated by electrical transducers. For example, the typical model train locomotive includes an electric motor that is energized by power that is conducted to the motor through the tracks and the locomotive's wheels from a power source. The locomotive's speed and direction can be controlled by varying the amplitude and polarity of the voltage applied to the track. This method of train control, now often referred to as the “legacy” mode, has been replaced, in substantial part, by a digital system in which a controlled device, such as a locomotive or a turnout, obtains operating power and control signals from a digital signal transmitted over the track. The digital system provides more flexible and realistic layout operation for an enhanced user experience.
Aspects of a digital control system for model train operation, known as Digital Command Control (DCC), are described by standards and recommended practices of the National Model Railroad Association Inc. (NMRA), which are incorporated herein by reference. DCC adds functionality to model locomotives and other controlled devices associated with model trains and model train layouts, such as lights and turnouts. Referring to FIG. 1, in a DCC model train system 20, each controlled device, such as a locomotive 22 or a turnout 24, includes an individually addressable decoder 26, 28 that responds to receipt of digital data, addressed to the particular decoder, by outputting an appropriate signal to control operation of a motor 30 or other transducer 32 actuating the controlled device. In response to an input at a user interface, a digital command station (DCS) 34 generates a decoder command in the form of a data packet, a set of encoded digital bits, which includes a digital instruction corresponding to the input and the address of the decoder of the particular controlled device that is to respond to the digital instruction. The digital command station 34 is connected by a control bus 36 to a booster 38. The booster 38, which is also connected to a power source 40, amplifies the voltage of the digital signals generated by the digital command station 34 and outputs a higher voltage digital signal to the track 40 or a substantially parallel, accessory bus. As a result, the controlled devices making up the layout and conductively connected to the track or the accessory bus can obtain both control signals and power from the, respective, track or accessory bus.
The user controls the train and other controlled devices of the layout by inputting commands to the DCC system through a user interface known as a “cab” or a “throttle.” The throttle is typically a handheld or a desk top unit that includes user operable controls for varying the speed and direction of a locomotive. In addition to the speed and direction controls, a throttle commonly includes a number of switches for controlling other features or functions of the train or the layout. For example a user controlled switch on the throttle may control the train's horn or interior lights. DCC throttles may also include selection controls permitting the user to select at least one of a plurality of locomotives in the layout that is to be operated by the throttle and may include a display to indicate the current settings of the operable controls of the throttle. A throttle 42 may be connected to the digital control system by a cab bus 44 that may include a number of plugs 46 permitting the throttle to be moved around the layout to enhance the user's experience when operating the layout or a portion of the layout. For even greater freedom of movement, a throttle 48 may be wirelessly connected to the digital command control system, typically, by infrared or radio communication.
To enable multiple users to control multiple trains and accessories in a layout, throttles may be connected to the digital command station 34 through a personal computer 50 that includes software that provides an interface to manage the signal traffic between several throttles and one or more digital command stations included in the layout. The present inventor has disclosed a system for controlling a model railroad in U.S. Pat. No. 6,270,040 B1 which is incorporated herein by reference. The model train control system comprises an layout controlling interface between one or more client programs and the digital command station(s) of a DCC layout. The client programs may include a throttle providing a user interface enabling user inputs to operate the layout. The client program outputs a request that is transported to the layout controlling interface by a communications transport. The layout controlling interface places the requests in the order in which they are received from the client program(s) and passes the requests to a digital command station which executes the requests by generating the corresponding DCC data packets for transmission to the controlled devices included in the layout. When a request is received, the layout controlling interface acknowledges the request to the client program releasing the communications transport for further transmissions. After execution, the digital command station passes an acknowledgement back to the layout controlling interface and the interface generates an additional asynchronous response to the client program to indicate that the digital command station has executed the user input. The response of the layout controlling interface to a user input reduces the time interval between a user input and an acknowledgement of the input at the user interface, enabling higher speed communication between the user and the control system and increasing user satisfaction with the operating experience without incurring the cost of a high bandwidth communication channel between the user interface and the digital command station.
While the layout controlling interface between the digital command station and the client program permits a plurality of users to share in operating a model train layout, the user experience is, in substantial part, the result of the user's satisfaction with the user interface that communicates the user's intentions to the DCC system. What is desired, therefore, is a user interface that is easy to set up and operate and provides a satisfying user experience.